Effects of prey density on the growth and survival of hybrid snakehead larvae

Abstract

The effects of prey density (0.1, 0.3, 1, 3 and 10 prey·mL^-1) on the growth and survival of hybrid snakehead (Channa argus × C. maculate) larvae were investigated. The larvae were divided into three groups with different body lengths of 0.68 cm, 1.50 cm and 3.20 cm, respectively. The growth of the hybrid snakehead larvae in all three groups increased with prey density increasing from 0.1 to 1 prey·mL^-1. The specific growth rate (SGR) was the highest when the prey density was 1 prey·mL^-1. When prey density was higher than 1 prey·mL^-1, SGR of larvae in Group I (the larvae of early development stage) decreased, while no significant change was observed in those of Group II and Group III. The survival rates of hybrid snakehead larvae in all three groups were high (91.11%–100%) and not significantly affected by the prey densities except in Group I with the highest prey density (10.0 prey·mL^-1) which was significantly lower than the others. Body size was not sensitive to prey density. The optimum prey density was confirmed at 1 prey·mL^-1 in all the treatments.

Keywords

hybrid snakehead / larvae, growth / survival / prey density